XXHighEnd

For the last week, I have been listening to music with the direct connection between the NOS1 and the power amplifier, as recommended. In other words: without the use of my preamplifier.

I used balanced cables (XLR - 6 feet) first, then reorganised  my system with longer balanced cables by installing the music PC, hard drives and NOS1 in another room, leaving only the power amp and speaker in the listening room.

Something is wrong. I don't have the same "presence", same rich SQ in this configuration - as opposed to having the preamp in the chain. The music sounds kind of lifeless when I use XXHighEnd digital volume. I even feel that I have lost some accuracy... ?

Am I missing something ?

Alain

Hi Alain,

Of course I cannot know what the pre-amp did for you in your system, but since getting my NOS1 a couple of months ago I have had a steady stream of dacs through to compare to it in my own system (due diligence for the NOS1 purchase if you like).  Included in these are the fully optioned MSB Analogue and Playback Designs MPD-3 and I must say that when compared to the NOS1 both of these dacs cannot produce the accuracy of reproduction nor generate for me the same emotional connection to the music.  The NOS1 soundstages at least as well as the MSB (and better than the PD) but outshines them both in speed, dynamics and detail retrieval, which are three of the things that infuses life into the music.  So when you say that the music sounds 'kind of lifeless' I know that the NOS1 should not be at fault.

My first thought would be your balanced cables.  One of the things I learnt from a thread on my local forum that Peter was kind enough to join is that the NOS1 will play nicely with very low capacitance interconnects.  Perhaps there is something to be gained there?

Anthony

EDIT: I should say that I have never used a preamp with the NOS1

I Anthony,

Thanks for this input. The store wher I bought theses cables is meant for musical instruments and it could be possible that the capacitance is higher than expected ? I used two different lengths (6 feet, then 75 feet). I questionned my choice about such a long cable, I may have been wrong to assume that since they were balanced cables with standard quality, it would not impair the SQ...

On the other hand... I am not sure that choosing a Spectral Audio power amplifier was the right choice. It can deliver a frequency response up to 1.8mhz and with the unfiltered output of the NOS1, it could harm the tweeters... That I have to check too...

Food for thoughts...

Regards,

Alain

I just checked the cable capacitance... It looks quite too high for what I was attempting to do... 46 pF/foot. This multiplied by 75 feet equals 3450 pF...

Ok, will try with the 6 feet version again, to see what it comes to...

Guess I forgot a few questions before getting these...

Alain
PS: This hobby can get quite frustrating when someone is acting "in the blind"... :(

This links gives specifications about the cables I bought.

http://www.digiflexcables.com/pdf/DFX%20NXX%20Sellsheet%20EN.pdf

Alain

Hi Alain,

A fellow has loaned me a set of these single ended cables (http://www.bluejeanscable.com/store/audio/index.htm) to compare with my expensive interconnects.  Note the Blue Jeans LC-1 capacitance of 12.2pF/ft (a third of the capacitance your cable claims).

I have not had a chance to spend much time with the loaner cable but I will throw it in now and let you know what I think.

EDIT:  The Blue Jeans cable is very good.  It is uncomfortably close to my high priced interconnect.

Cheers,

Anthony

Alain,

I can imagine that you now need to attenuate too much ?
More than 48dBFS is a no-go anyway.

Peter

Hi Antony,

After my last post, I disconnected the preamp and tried again with the 6 feet XLR cables. Quite a difference, even if they stiill have a high capacitance. At least it proves to me that my plan on moving a part of my equipment, while a good idea at first, had a serious flaw... Thanks for your help !

I do have good single ended ICs, but I wanted to use the balanced cables path...

And yes, I am considering BJC for the replacement :)

Regards,

Alain
Well.. Unless I do not understand the question correctly... No ? With the preamp, I have more range for the level (up to 8V)...

Funny you mention this 48dBFS, because I read the documentation about the NOS1 once again last evening...

I had moved my equipment, plugged, unplugged, plugged again quite often for the recent months (ground loop and this)... I think I will rest from that... After I have decided what to do with my subs !!! Because if I decide to keep them, the preamp will again have its place in the equation...  :scratching:

Alain

Ok Alain, I can't get what you are saying ...

The -48dBFS attenuation is from XXHighEnd. So, when you need to attenuate this much it ain't good.
That is really all !

Peter

I was wondering... About this project about putting part of the system in another room... What would be the maximum "acceptable" total capacitance before a degradation occurs between the dac and the power amp ? Aren't balanced cables supposed to allow for good signal transfer through some length ?

I would need about 36 feet of cables to accomplish this project...

Alain

Hey Alain,

Balanced cables are about eliminating noise; this has not much to do with frequency roll off or being able to drive the amp.

Your 12 meters would allow for something like 12nF for the total length and then 192KHz native frequency still is OK (and no instruments reach that frequency, so, always OK). However :

Assumed that 50pF/meter is doable (to get), the total of 600pF can be driven by your NOS1.

Regards,
Peter

Thanks :)

Alain